Conventionally, a rotary damper has been known that comprises a hollow housing which is opened at its one end and completely closed at the other by an end wall, a bearing formed in the end wall, a shaft fitted to the bearing, a plug having an aperture supporting the shaft and closing an opening in the housing, a partition arranged inside the housing for rotation in accordance with rotation of the housing, viscous liquid filling chambers defined by the partition, and a vane arranged in the chamber for rotation in accordance with the rotation of the shaft (see, e.g., JP 2008-082462 A).
In this kind of the rotary damper, the end wall completely closes the other end of the housing. Therefore, when the housing or the shaft rotates, the viscous liquid flows into a space between the bearing and the shaft to float the shaft. Consequently, the vane slides in the state where it is pushed against the plug. When both the plug and the vane are made of metal, abrasions occur on both the plug and the vane, resulting in a problem of deteriorating characteristics.